The present invention relates to a biomedical signal cable that connects a detection section that detects a biomedical signal and a biomedical signal processor capable of processing the biomedical signal detected by the detection section and transmitting the processed data by radio with a signal wire and a biomedical signal processor that uses the above described cable as an antenna wire.
As a conventional biomedical signal processor that attaches biomedical electrodes to an examinee, collects a biomedical signal such as an electrocardiogram and transmits the collected biomedical signal by radio to a monitor device, etc., a medical telemetery apparatus is used.
This type of medical telemetery apparatus is attached to a patient when it is necessary to constantly monitor a biomedical signal like an electrocardiogram of the patient and it is more and more miniaturized out of the necessity for minimizing a burden on the patient and many portable telemetery apparatuses are currently in use.
Thus, providing a separate antenna wire for the apparatus constitutes an obstacle to the use of the apparatus. Moreover, the biomedical signal, for example, an electrocardiogram signal is a frequency not so high as a radio transmission frequency. Considering these reasons, a biomedical signal cable that connects the biomedical electrode and the medical telemetery is generally used also as an antenna for the biomedical signal processor.
However, in the case of the medical telemetery that uses the biomedical signal cable also as the antenna, the tip of the biomedical signal cable is connected to a biomedical electrode and thereby electrically connected to a living body, which causes a problem that the antenna efficiency deteriorates.
The present invention has been achieved to solve the above described problems and it is an object of the present invention to provide a biomedical signal cable which keeps high antenna efficiency when used also as an antenna wire and a biomedical signal processor using this biomedical signal cable. As means for attaining the above object, the present invention adopts, for example, the following configurations.
That is, the present invention provides a biomedical signal cable that connects a detection section that detects a biomedical signal and a biomedical signal processor capable of processing the biomedical signal detected by the detection section and transmitting the processed data by radio using a signal wire, characterized by including a first connection section connected with the biomedical signal processor and a high resistance section with high resistance for the transmission frequency, provided at a position away from the first connection section by approximately a xc2xc wavelength of the transmission frequency sent by radio by the biomedical signal processor.
Alternatively, the present invention also provides a biomedical signal cable that connects a detection section that detects a biomedical signal and a biomedical signal processor capable of processing the biomedical signal detected by the detection section and transmitting the processed data by radio using a signal wire, characterized by including a first connection section connected with the biomedical signal processor and resonance sections that resonate with a transmission frequency to increase the resistance for the transmission frequency, provided at a position away from the first connection section by approximately a xc2xc wavelength of the transmission frequency sent by radio by the biomedical signal processor and at a position away from the above described position by approximately a xc2xd wavelength of the above described transmission frequency.
Furthermore, for example, the above described resonance section is characterized to be a conductive member fixed to the signal wire. Or the conductive member of the above described resonance section is characterized to be a ferrite core. Or the conductive member of the above described resonance section is characterized to be a conductive metallic cylinder that the signal wire penetrates and electrically connected with a grounding signal wire and electrically resonating with a xc2xc wavelength.
Furthermore, the above described resonance section is characterized to be formed by shaping the signal wire like an air-core coil. Or the above described resonance section is characterized in that the signal wire is shaped like an air-core coil and a parallel resonance circuit is formed by the resonance section together with an electrostatic capacitance element connected between both ends of the air-core coil of the signal wire to resonate with the resonance frequency.
Furthermore, the present invention provides a biomedical signal processor that is fed a biomedical signal from the detection section connected to the signal cable according to any one of the aforementioned embodiments via the cable, carries out predetermined processing and transmits the processing result by radio using the signal cable as an antenna.